According to this ACLU link the government claims to have
the power of warrantless search & seizure 100 miles in from any
international boarder. 2/3rds of the US population unwittingly lives
with in this ring around the boarders. Another interesting aspect that
the ACLU does not get into is that when they create these NAFTA super
highways (that are considered international roads not necessarily owned
by the US) these 100 mile buffer zones could extend all through the US.
Another theory could include any airport that accept international
flights.